ext4: validate external journal superblock checksum

If the external journal device has metadata_csum enabled, verify
that the superblock checksum matches the block before we try to
mount.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Darrick J. Wong 2014-09-11 11:44:36 -04:00 committed by Theodore Ts'o
parent feb8c6d3dd
commit df4763bea5

View File

@ -4414,6 +4414,15 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
goto out_bdev;
}
if ((le32_to_cpu(es->s_feature_ro_compat) &
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
es->s_checksum != ext4_superblock_csum(sb, es)) {
ext4_msg(sb, KERN_ERR, "external journal has "
"corrupt superblock");
brelse(bh);
goto out_bdev;
}
if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
ext4_msg(sb, KERN_ERR, "journal UUID does not match");
brelse(bh);